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Respiration assistor

Imported: 24 Feb '17 | Published: 06 Jan '04

Graham Cameron Grant

USPTO - Utility Patents

Abstract

A respiration assistor (

10) for use in an anaesthesia breathing system. The respiration assistor is intended to provide respiratory assistance for a patient (

14) who is breathing spontaneously under anaesthesia in order that the patient's end-expired CO

2 will be maintained at or near the normal physiological level. For this purpose, the respiration assistor incorporates a blower (

15) which is located in series with a gas flow detector (

20 or

39) and an electric control circuit (

19) is provided for activating the blower (

15) when inspired gas flow is detected by the detector (

20 or

39). Also, the respiration assistor incorporates an expiratory valve (

23) that is actuated to a closed condition when the blower is activated. The respiration assistor is intended to be activated as and when required by an anaesthetist to provide in-phase respiratory assistance to a patient who is breathing spontaneously and, in any case, the respiration assistor remains in-circle with and does not affect the normal function of an associated circle absorber.

Description

The invention will be more fully understood from the following description of embodiments of a respiration assistor for use in an anaesthesia breathing system. The description is provided with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings

FIG. 1 provides a schematic illustration of a preferred embodiment of the respiration assistor and a connected gas conditioning-supply circuit,

FIG. 2 provides a schematic illustration of an alternative embodiment of the respiration assistor and, again, a connected gas conditioning-supply circuit,

FIG. 3 shows one way of removably coupling a blower to an electric drive motor in the respiration assistors of FIGS. 1 and 2, and

FIG. 4 shows one form of a solenoid operated expiratory valve for use in the respiration assistors as shown in FIGS.

1 and

2.

Claims

1. A respiration assistor for use in an anesthesia breathing system for providing in-phase respiratory assistance to a spontaneously breathing patient and which comprises:

2. The respiration assistor as claimed in claim 1 wherein the pressure booster further comprises a motor which drives the blower.

3. The respiration assistor as claimed in claim 2 wherein the pressure booster comprises a motor driven centrifugal blower having a vaned drum rotor through which inspired gas may be drawn by a patient.

4. The respiration assistor as claimed in claim 2 wherein the blower is removably coupled to the motor.

5. The respiration assistor as claimed in claim 3 wherein the rotor has a shaft that mates in sliding, press-fitting engagement within a bore of a drive shaft of the motor.

6. The respiration assistor as claimed in claim 2 wherein the control circuit is arranged to effect energization of the motor only when the blower is to be activated.

7. The respiration assistor as claimed in claim 2 wherein the control circuit is arranged to effect constant energization of the motor and to effect coupling of the blower to the motor when the blower is to be activated.

8. The respiration assistor as claimed in claim 3 wherein a drive shaft for the rotor passes through a membrane to couple with a rotor shaft of the motor, and wherein the membrane is removably secured within a casing of the centrifugal blower.

9. The respiration assistor as claimed in claim 2 wherein a gas flow activated inspiratory valve is located in the first gas supply passage.

10. The respiration assistor as claimed in claim 9 wherein the gas flow detector is integrated in the inspiratory valve.

11. The respiration assistor as claimed in claim 10 wherein the gas flow detector includes a photoelectric sensor which is arranged to provide an output signal that indicates the existence of inspired gas flow with opening of the inspiratory valve.

12. The respiration assistor as claimed in claim 2 wherein the electrically actuatable expiratory valve comprises a solenoid actuated valve member that normally is biased into an open condition but which is arranged to be actuated to a closed condition upon detection of inspired gas flow through the gas flow detector.

13. The respiration assistor as claimed in claim 12 wherein the electrically actuatable expiratory valve comprises a valve casing and wherein a valve member is carried by a diaphragm that is removably secured within the casing.

14. The respiration assistor as claimed in claim 2 wherein a fault indicator is electrically connected to the control circuit, and wherein the control circuit is arranged to generate and apply a fault condition signal to the fault indicator if gas is not detected to flow through the gas flow detector for a time interval that exceeds a predetermined time interval.

15. The respiration assistor as claimed in claim 14 wherein the control circuit is arranged also to generate and apply a fault condition signal to the fault indicator if an uninterrupted flow of gas is detected in the gas flow detector.